Recherche des métastases ganglionnaires des mélanomes malins après isolement du ganglion sentinelle par lymphoscintigraphie préopératoire et détection radio-isotopique peropératoire. Résultats préliminaires

Abstract

Detection of lymph node metastases in malignant melanoma after identification of the sentinel lymph-node with preoperative lymphoscintigraphy and intra-operative radio-isotopic detection. Preliminary results Objectives: The aim of this study was to evaluate the detection of the first lymph node draining the primary tumour site, using a radioisotopic mapping alone and to determine whether a preoperative lymphoscintigraphy using technetium sulfur colloid and a hand-held gamma detecting probe could improve the detection of the sentinel lymph node (SLN) in melanoma. Patients and method: From January to December 1998, 36 patients with a cutaneous melanoma larger than 0,75 mm, stage I TNM were included in this prospective study. Mean Breslow was 1,85 mm. The distribution of melanoma was head and neck ( n=9), trunk ( n=7), upper extremities ( n=4), lower extremities ( n=16). Preoperative lymphoscintigram and intraoperative detection were used. The first hot lymph node was supposed to be the SLN. Results: In all cases, a lymph node was found and nine patients had more than one SLN (average number of SLN per patient: 1.25). Aberrant drainages were found in seven patients (19.4 %) : 1 in-transit lymph node, three paradoxical bassins, three bypasses). Four out of 36 patients had lymph node metastases and underwent elective lymph node dissection. Conclusion: The radio-isotopic technique used alone for the identification of the SLN is efficient in melanoma with a 100 % detection rate in this short series.